Spreader stoker apparatus



Dec. 1945- w. KESSLER SPREADER STOKER APPARATUS Filed July 21, 1943 2 Sheets-Sheet l INVENTOR m/bur Kass/er Q @aCBMm ATTORNEY W. KESSLER SPREADER STOKER APPARATUS Filed July 21, 1943 FIG. 6

2 Sheets-Sheet '2 INVENTOR mm Aessler BY I V ATTORNEY Patented Dec. 4, 1945 SPREADER STOKER APPARATUS Wilbur Kessler, Newtown Square, Pa., assignor to Westinghouse Electric Corporation, East Pittsburgh, Pa., a. corporation of Pennsylvania Application July 21, 1943, Serial No. 495,549

1 Claim.

This invention relates to stokers, more particularly to stokers of the spreader" or sprinkler type, and has for an object the provision of novel fuel-spreading mechanism.

Another object of the invention is to provide improved fuel-impelling apparatus for use with spreader type stokers.

Yet another object of the invention is to provide means for obtaining improved distribution of fuel longitudinally of the stoker grate.

A further object of the invention is to provide, in spreader stoker mechanism, fuel-impelling means in the form of a rotary member having a plurality of fuel-projecting blades carried thereby, the blades being of different lengths to provide for variations in the travel of the fuel im- Pelled thereby.

These and other objects are effected by the invention as will be apparent from the following description and claim taken in accordance with the accompanying drawings, forming a part of this application, in which:

Fig. 1 is a transverse sectional view through a spreader stoker mechanism embodying the principles of the present invention;

Fig. 2 is a plan view of the structure shown in Fig. 1, with portions thereof broken away for the sake of clearness;

Figs. 3, 4 and 5 are enlarged sectional views of three modifications of the present invention;

Fig. 6 is a longitudinal elevational view of a rotor constructed in accordance with the invention; and

Fig. 7 is a sectional view taken along the line VII-VII of Fig. 6, looking in the direction indicated by the arrows.

Referring now to the drawings more in detail, and particularly to Figs. 1 and 2, the reference character I0 indicates, in its entirety, spreader mechanism for delivering fuel through the opening II, in the front Wall I2 of the furnace l3, to the grate structure I4 within the latter.

The spreader mechanism comprises a hopper Hi from which fuel discharges by gravity to the bottom plate ll of the ram box l8. As best indicated in Fig. 2, the ram box is provided with a plurality of vertical partitions l9 extending from front to rear thereof and serving to space the series of rams 20, 2 I, 22 and 23.

Reciprocatory motion is imparted to the rams through a linkage arrangement comprising links 26 or 21 connected at one end to a ram and at the other end by pivot pins 29 to one end of a bar 28, fixedly secured on the vertical shaft 30, which shaft is journaled for limited rotary motion in the lower and upper support pl es 3 an 32, respectively, carried by the rambox structure l8. Extending rearwardly from each vertical shaft 30 is a lever arm 34, disposed at right angles to the arm 28 and having its free end pivotally connected to the transversely-extending shaft or bar by pins 36. Transverse reciprocatory motion is imparted to the bar 35 by suitable means, such as the engine 31, operating through the link 38, having a slot-and-pin connection 39 with the bar 35.

In order to prevent clog ing of the ram structure by fuel sittings working forwardly into the ram box, the latter is provided with an interior groove or recess lll having inlet and outlet connections 41a and llb, respectively, whereby air or liquid may be continuously passed through the groove to remove sifting finding their way thereto through the joints between the rams and the ram box structure.

Fuel, pushed rearwardly from the bottom plate of the ram box structure by reciprocation of the rams, moves over the supporting plate 42, upon which a plurality of spill plates 43, 44, and 46 are adapted to reciprocate.

As best illustrated in Fig. 2, the number of spill plates preferably coincides with the number of rams, and the corresponding spill plates and rams are arranged to reciprocate in phase, that is, when ram 20 moves rearwardly its corresponding spill plate 43 likewise moves rearwardly. Also, it will be noted that alternate spill plates and rams (20, 43 and 22, 45) reciprocate in one direction when the remaining spill plates and rams (2|, 44 and 23, 46) reciprocate in the opposite direction, this arrangement providing for more uniform feed of fuel than would be possible if all of the rams were advanced and retracted in' unison. However, it will be apparent that corresponding spill plates and rams may bereciprocated out of phase, and that all spill plates and/ or all rams may reciprocate in unison or in any desired manner.

The means herein illustrated for reciprocating each spill plate comprises a rod 48 connected at its rearward end to the forward portion of the spill plate and having at its forward end a depending lug 49, which is bifurcated to receive the rearward end 50 of a connecting link 5|, the end 5|] being secured within the bifurcation of the depending lug 49 by the pin 52, for pivotal movement. The forward end of the link 5| is secured by pin 53 between the arms of the bifurcated lever 54, which is fixedly secured to the lower portion of the vertical shaft 30. Preferably, each member 54 is of double-arm construction, and has attached to the other arm linkage similar to that just described, for operating the adjacent spill plate. Preferably, there is included in each link 5!, suitable stroke-adjusting mechanism, indicated at 55. Inasmuch as the stroke-adjusting mechanism comprises no part of the present invention, it is indicated only schematically in the accompanying drawings.

In order that the spill plates may reciprocate freely beneath the fuel being fed rearwardly thereover, the plates are tapered at their forward edges, as at 58, with the result that they may easily slide beneath the fuel deposited upon the supporting plate 42. It will be apparent that reciprocation of the spill plates provides for feeding of fuel to the impeller or rotor mechanism 59, from points varying from rearwardly of the vertical centerline of the rotor to forwardly thereof, with the result that the fuel is projected through angles varying from the horizontal, t ereby providing improved distribution of fuel lengthwise r the grate structure 14,

The impeller 59 comprises a horizontally-disp sed h llow bo y member or drum 60, having mounted thereon and extending radially therefrom a plurality of lades BI and 62, the blade 6| being of greater length than the blade 62, and the impeller structure being enclosed by a housing 63, disposed in close proximity to the P of travel of the longer blade 6|, It will be apparent that, due to the blade 6| being of gr ater length radially than the blade 52,, the outer portion thereof will have sreater linear velocity than the corresponding portion of the shorter blade 62, with the result that the fuel, projec ed rearw rd y thereby through the front wall op ning I I, will travel farther than the fuel projected by the sh rter blade 6 having a. lower linear velocity.

In Fig. 4, there is illustrated a modification of the tructure o Figs. 1 to 3, wherein the hum.- ber of blades is increased to three, the blad s being a ran d in order of in re sing length in the direction opposite to the rotation of the impeller. In other words, as the blades reach the p t at which the fuel falls from the outer end of the spill plates 43, 44, 45 and 46, the fuel will first be struck by the shortest blade 66, then by the intermediate blade 61 and finally by the longest blade 88, after which the cycle will be repeated up n subsequent revolutions of the imrol er 6 T e modification of Fig, 5 provides four blades ll, 12, 13 and 14, p sitioned 90 degrees apart circumferentially about the body member 10. Preferably, these blades likewise are arranged in the order of in easing height as they pass a fixed point during their revolution, as in the structure of Fig. 4.

In Figs. 6 and 7, there is illustrated an arrangement wherein the rotor shaft 8!] has mounted thereupon, in side-by-side relation, a plurality of impeller units 8|, 82, 83 and 84, each of these units comprising a hub portion 86 having an internal key 81, adapted to be received in one of the four keyways 88, provided in the outer surface of the rotor shaft 80, and spaced 90 degrees apart thereabout. Each of the impeller unit hubs '86 has four blades of different lengths formed thereon or secured thereto, the blades being indicated by the reference numerals l, 2, 3 and 4 in the order of their increasing length, from the shortest to the longest. Preferably, each of the four impeller units is mounted on the shaft with its key 81 in a different keyway 88. Inasmuch as each key 81 is formed opposite the shortest blade I, the entire assembly of units may produce a composite blade structure in which each longitudinally-extending and aligned composite blade is made up of four sections or portions, each of a difierent radial length. Preferably, each of the impeller units, starting from one end of the shaft, is disposed with its blade arrangement degrees back of the preceding impeller unit, as illustrated in Fig. 6. This will result in each longitudinal composite blade unit, for example, sections l, 2, 3 and 4 at the top of Fig. 6, delivering fuel simultaneously to'various sections of the furnace grate area, considered in the front to rear direction thereof.

While the invention has been shown in several forms, it will be obvious to those skilled in the art that it is not so limited, but is susceptible of various other changes and modifications without departing from the spirit thereof, and it is desired, therefore, that only such limitations shall be placed thereupon as are specifically set forth in the appended claim.

What is claimed is:

In a Stoker, a rotary fuel impeller comprising a rotatable body member and a plurality of fueldistributing elements carried thereby in sideJay- Side relation; each of said elementscomprising a hub and an annular series of outwardly-extendins blades carried thereby, said blades varying in length from hub to tip, the fuel-distributing elements having similar arrangements of the blades in their series, with each series out of phase with the adjacent series by the annular spacing of the blades, and the number of blades on each element being evenly divisible into the number of elements on the body member, whereby a balanced propeller structure is provided.

. WILBUR KESSLER. 

